Lecture 1: Introduction
Dr. Mamoun Ahram
Faculty of Medicine
Second year, Second semester, 2014-2014
Principles of Genetics and Molecular Biology
Syllabus and references
Part I: Cell biology (Dr. Mamoun Ahram)
The Cell: A Molecular Approach, Geoffrey M. Cooper
and Robert E. Hausmann, 6th edition, Sinauer
Associates, 2013.
Part II: Molecular biology (Prof. Said Ismail)
Mark's Basic Medical Biochemistry, Smith, Marks
and Lieberman, Lippincott, Williams and Wilkins,
2009.
Part III: Genetics (Prof. Mohammad El-Khateeb
Emery's Elements of Medical Genetics, Muller &
Young, Churchil Livingstone, 13th edition, 2011.
The origin of life
DNA homology
Humans and others
“We are all Arabs”!!
Arabia was indeed the first staging post in the spread of
modern humans around the world.
The American Journal of Human Genetics 90, 1–9, February 10, 2012
Genetic relatedness of world populations
Cavalli-sforza et al., 1988
Hum Immunol. 2001 Sep;62(9):901-9.
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Prokaryotic cells (E. coli)
Simple, rapid growth, small
genome.
They are ideal models to
study basics of biochemistry
and molecular biology.
E. coli is used to understand
basic mechanisms of
molecular genetics.
It has ~4.6m base pairs/4300
genes/1 chromosome.
They cannot be used to study aspects of
eukaryotic cell structure and function.
Yeast
The simplest eukaryotes with
features of eukaryotic cells.
A distinct nucleus surrounded by
a nuclear membrane
A cytoskeleton and subcellular
organelles
Growth is rapid and as
colonies.
12 million base pairs of
DNA/6000 genes/ 16
chromosomes
Used to understand DNA replication,
transcription, RNA processing, protein
sorting, and regulation of cell division.
Dictyostelium discoideum
A cellular slime mold
More complex genome than
yeast’s, but simpler than that
of higher eukaryotes’.
can be readily grown in the
laboratory and undergo
genetic manipulations
Highly mobile cells used to
study molecular mechanisms
of animal cell movements.
Single cells can aggregate
into multicellular structures
Caenorhabditis elegans
More complex eukaryotes
97m base pairs of DNA/~19,000
genes/6 chromosomes
easily grown in lab and genetically
manipulated
Adult worms consist of only 959
somatic cells starting from 1090.
used for studies of animal
development and cell
differentiation and apoptosis
Drosophila melanogaster
(The fruit fly)
180m base pairs, four chromosomes, 14,000 genes
Easily maintained and bred in the laboratory with
short reproductive cycle (~2 weeks)
• unravel genes involved in development and
differentiation
• Determine the relationship between genes
and chromosomes
Xenopus laevis (a frog)
used in studies of early
vertebrate development.
Xenopus eggs are large (a
diameter of ~ 1 mm) and
develop outside of the
mother
stages of development can be
studied in the laboratory.
Used in studying
development,
differentiation, and
embryonic cell division.
Mice
3000m base pairs, 20,00025,000 genes/20
chromosomes
Transgenic mice with
specific mutant genes
introduced into the mouse
germ line
Cultured mammalian cells
Mammalian cells are
isolated, get immortalized,
and grown in dishes
can be manipulated under
controlled laboratory
conditions.
Uses: many aspects of
mammalian cell biology,
(DNA replication, gene
expression, protein
synthesis and processing,
and cell division, etc.)
Viruses
intracellular parasites
They reproduce by infecting
host cells and taking over the
cellular machinery.
In their simplest forms, viruses
consist of genomic nucleic acid
surrounded by a protein coat.
Bacteriophages (bacterial
viruses) allowed understanding
basic molecular genetics.
Organelles